Rainwater Harvesting and Water Management Systems for Greener Living

From both an environmental and economic perspective, the difference of having a small scale water management at home can be significant to homebuilders and developers.

According to Save the Rain, a campaign in the United Kingdom that champions rainwater harvesting in construction, a rainwater harvesting system alone can save the domestic water user 30 to 50 per cent and the commercial user up to 80 per cent on their water bills.

The American Society of Landscape Architects also points out that natural stormwater management technologies "reduce the massive energy costs associated with running complex stormwater management systems."

Rainwater harvesting

Rainwater harvesting is the collection and storage of rainwater for domestic or commercial use. In an urban setting, rainwater from roof runoff can also be collected in storage tanks. Besides reducing energy use, there are a number of advantages to harvesting rainwater:

• Even without a water purification system, rain water storage tanks can provide water for irrigation, toilet flushing, clothes washing and other needs.
• Rainwater tanks help reduce flooding and soil erosion.
• The cost of rainwater harvesting systems is less than the cost of water purification and pumping systems.
• Collecting stormwater also reduces the demand on local water supply, helping to save water in the community.

The initial cost of installing a rainwater harvesting system could amount to a considerable sum, depending on its size, complexity and whether it's installed above or below ground. However, owners of GBI certified homes may be entitled to government tax incentives, which have been extended to 2020.

Natural stormwater management technologies

There are some natural stormwater management methods in place that are used today. These include cement gutters in the typical urban environment, which diverts stormwater into an underground piping system.

Bioswales are vegetated, mulched or xeriscaped (landscaping that reduces or eliminates the need for irrigation) channels that slow the movement of stormwater runoff and filter the water. Bioswales are recommended for use on residential streets and parking lots.

Individual homes, residential developments and business centres can reduce the risk of flooding and manage runoff by installing detention systems, also known as bio-retention systems (or ponds) and can be either large or small in size depending on their location.

Dry and Wet Retention Systems

Dry systems work by feeding rainwater directly into a water tank naturally (by gravity) after each downpour. The tank is usually stored next to the property (above ground) and is great option for climates like Malaysia where moderate rainfall occurs with large storms.

In a wet system however, collected rainwater is filtered into underground pipes and is channeled back up via a riser pipe located near the tank. Rainwater fills the underground piping and the water rises up into the tank. Because the pipes are underground and the water storage tank can be located away from the home, wet systems tend to be more aesthetically pleasing than dry systems. However, this means extra costs due to the additional piping that needs to be implemented.

As green technologies become further implemented in residential properties, water management systems can prove to be an environmentally friendly and cost-effective way to reduce one's carbon footprint while managing effectively managing a home's much-needed supply of water.

[Image Source: Flickr]